A toxicity report from the phase II ASTEROID study demonstrated that durvalumab administered after stereotactic body radiotherapy (SBRT) in patients with early stage non-small cell lung cancer (NSCLC) was well tolerated, according to findings presented at the European Lung Cancer Virtual Congress 2021 (25-27 March).

Andreas Hallqvist of the Institute of Clinical Sciences, Sahlgrenska Academy, Department of Oncology, Sahlgrenska University Hospital in Göteborg, Sweden presented the results of the randomised multicentre open-label phase II ASTEROID study (EudraCT: 2016-005225-37; NCT03446547).

He explained that, while SBRT is associated with excellent local control, approximately 30% of patients develop distant metastases over time. Due to a lack of data and the fragility of this patient population, adjuvant chemotherapy is rarely administered. Therefore, Dr. Hallqvist and colleagues investigated immunotherapy, which has less toxicity and may provide a potential synergistic effect, as a treatment option. The investigators evaluated whether durvalumab in combination with radiation could improve outcomes in patients with T1-2N0M0 NSCLC.

Twenty-five patients in arm A were treated with 3 to 4 fractions of SBRT only, whereas 22 patients in arm B received the same SBRT regimen followed by adjuvant treatment of 1500 mg durvalumab every 4 weeks. Most (66%) of the patients were women with a median age of 76 (range, 58 to 89) years. Adenocarcinomas were reported for 66% of the patients; 28% were ECOG performance status (PS) 0, 51% PS 1, and 21% were PS 2. The majority (98%) of the patients were former or current smokers and the mean FEV1 was 1.6 (0.64-4.5) L.

The primary endpoint was time to progression (TTP), but the present analysis is an initial safety report.

Durvalumab addition increased the number of adverse events but most were grade 1 or 2

Among all 47 patients included in the primary report and in the 24 patients completing treatment, the median number of durvalumab infusions was 6 (range, 1 to 12) and 11 (range, 3 to 12), respectively.

Adverse events (AEs) per Common Terminology Criteria for Adverse Events (CTCAE) v4.0 related to SBRT were reported in 7 (28%) patients in arm A and in 6 (27%) patients in arm B. All of the SBRT-related AEs were grade 1-2 events and consisted of pneumonitis, cough, dyspnoea, skin reactions, fatigue, and pain.

Of the patients receiving durvalumab in arm B, 12 (55%) reported durvalumab-related AEs that were primarily grade 1 or 2; the most commonly reported events were skin reactions and/or rash in 45% of patients, pruritus in 27%, and 18% of patients had thyroid disorders. Grade 3 AEs occurred in 6 patients; 2 patients had grade 3 pneumonitis, one patient had dyspnoea, and 3 patients had grade 3 asymptomatic hepatitis. One patient receiving durvalumab had grade 4 asymptomatic increased lipase.

Safety-Analysis-Shows-that-Durvalumab-Treatment-After-SBRT-Is-Feasible-in-Patients-with-Early-Stage-NSCLC

The addition of durvalumab to SBRT in early stage NSCLC patients seems feasible and well tolerated.

© Andreas Hallqvist.

Regarding the primary efficacy endpoint, TTP data were not yet mature.

Conclusions

The investigators remarked that SBRT followed by adjuvant durvalumab appears to be feasible and well tolerated.

The study is continuing to enrol participants as planned and to assess the primary endpoint of TTP.

This study was funded by AstraZeneca.

Reference

63MO – Hallqvist A, Koyi H, de Petris L, at al. Safety analysis of durvalumab following stereotactic body radiotherapy (SBRT) in early-stage non-small-cell lung cancer (NSCLC) patients – A first report of a randomized phase II trial (ASTEROID). European Lung Cancer Virtual Congress 2021 (25-27 March).

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